Solutions for machining workpieces by means of a laser beam have been disclosed in the prior art, of which only patent specification U.S. Pat. No. 6,335,508 B1 is referenced as an example herein. In it, delivery means for pipes are described, which can be used for machining pipes by means of a laser beam. A rotationally symmetrical pipe is retained by means of a plurality of transport devices and transported along its longitudinal axis. An additional controlled rotation of the pipe around its longitudinal axis makes it possible to machine the pipe by means of a laser cutting head using a variety of cutting controls.
Special requirements involving the process control and the design of devices for laser cutting are needed for machining non-rotationally symmetrical workpieces. In order to guide cuts along the proposed machining lines, the exact spatial orientation of the workpiece must be known in addition to the position. While it is for example sufficient to know that the longitudinal center axis of the workpiece is positioned in a specified X-Y plane for machining a rotationally symmetrical workpiece, the additional knowledge of the orientation in the X-Y plane (e.g. orientation of the front or back end of the workpiece) and the orientation of the workpiece in Z-direction is required.
Furthermore, it is known to apply markings to non-rotationally symmetrical workpieces, for example to bent pipes (e.g. DE 36 19 643 A1), to mark the site of an object to be mounted on the pipe later on. In so doing, the marking can be applied during or after the pipe is bent in a bending machine, as long as the pipe is still inside the bending machine and the exact position and the spatial orientation of the bent pipe are therefore known. The application of the marking at a later time is only possible if the pipe was transported across known trackages and with known angles of rotation, and the exact position and hence the spatial orientation of the non-rotationally symmetrical pipe (workpiece) are additionally known. After removing the workpiece from the bending machine, a spatial orientation of the workpiece, and hence e.g. the location and direction of the machining lines, is only possible with the help of complex metrology (e.g. 3D scanners). Therefore, a subsequent further machining of the workpiece is associated with complex time- and compute-intensive determinations of the spatial orientation of the workpiece, as a result of which the required cycle times for machining a single workpiece increase.